We can make mac to boot in verbose mode permanently (i.e, show all log messages during boot) by setting the "nvram" variable in terminal. $ sudo nvram boot-args="-v" This will set the mac to show verbose messages when every time mac os x boots.

To reset back again, run : $ sudo nvram boot-args=

Note : If you want to see the verbose messages for momentarily then hold " Command+V " during the mac booting immediately after mac starts booting

Firmware and boot ROM version of your mac can be found in two ways. Way 1 : 1. From "Apple" menu , choose "About This Mac" menu item. 2. Click " More Info " to open "System Profiler" application. 3. Under Contents -> Select Hardware Tree item. On the right side panel Under hardware overview section, we can see Boot ROM Version and SMC (Firmware) Version.

We can change the default shell of a user by using "usermod" command as below. $ sudo usermod -s "name of the shell" "username" This command will set the default shell for the username supplied as argument above in the command.

We can also use "chsh" command to change the user default shell as below